Assuming I understand what you're saying., there can be several reasons and solutions: 1) are you looking at the figure through the posing camera? If so change the camera. 2) How are you identifying the motion displacement. Often a BVH file will only define the body's movement relative to itself. You can identify this be looking at the animation pallette. If there are no keyframes indentified at the start and end of each cycle then you will not have movement through space. 3) When you save it to the library are you saving the body as well as the body parts?